Testing on an 8-socket AMD server with Opteron 885 dual-core processors
(16 cores total) and a Sun T5120 (T2 Niagara 8 cores, 64 hardware
threads) has shown that our current frontend code is performing very
poorly with more than 16 server threads.

You mention one particular hardware architecture here.

Not just one - the Sun T2 Niagara is a quite different architecture from
AMD/Intel. We also test on Itanium and PA-RISC, though less often. And of
course, anyone with a system that they'd like to see tested is welcome to
provide us access to conduct such tests. The 8-socket AMD server I mentioned
above is based at a company in Singapore. As long as we can get network access
and they can provide load generator machines on the same LAN as the target
server, it doesn't really matter where the machine resides.
--
-- Howard Chu
Chief Architect, Symas Corp. http://www.symas.com
Director, Highland Sun http://highlandsun.com/hyc/
Chief Architect, OpenLDAP http://www.openldap.org/project/